Nguyen Ngoc Long scored the only goal for Vietnam and ostensibly booked Vietnam's berth into the semi-finals just four minutes after both teams returned from the tunnel.

The squad will line up in what is a dead rubber against neighbours Laos in the last match of Group B on August 28.

Nine teams from the Association of Southeast Asian Nations (ASEAN) member countries, except the Philippines, have been divided into two groups.

Group A includes Brunei, host Cambodia, Indonesia, Malaysia and Thailand, while group B consists of Laos, Myanmar, Singapore and Vietnam. The top two from each group will advance to the semi-finals.